Commit f5c5a36d authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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tty: moxa: rework the locking a bit 



Introduce a lock for moxafunc() to protect the cases where were get collisions
between two function requests at the same time.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent f176178b

drivers/char/moxa.c

+22 −5
Original line number Diff line number Diff line
@@ -248,9 +248,25 @@ static void moxa_wait_finish(void __iomem *ofsAddr) 


static void moxafunc(void __iomem *ofsAddr, u16 cmd, u16 arg)

{

        unsigned long flags;

        spin_lock_irqsave(&moxafunc_lock, flags);

	writew(arg, ofsAddr + FuncArg);

	writew(cmd, ofsAddr + FuncCode);

	moxa_wait_finish(ofsAddr);

	spin_unlock_irqrestore(&moxafunc_lock, flags);

}



static int moxafuncret(void __iomem *ofsAddr, u16 cmd, u16 arg)

{

        unsigned long flags;

        u16 ret;

        spin_lock_irqsave(&moxafunc_lock, flags);

	writew(arg, ofsAddr + FuncArg);

	writew(cmd, ofsAddr + FuncCode);

	moxa_wait_finish(ofsAddr);

	ret = readw(ofsAddr + FuncArg);

	spin_unlock_irqrestore(&moxafunc_lock, flags);

	return ret;

}



static void moxa_low_water_check(void __iomem *ofsAddr)
@@ -417,6 +433,7 @@ static const struct tty_port_operations moxa_port_ops = { 
static struct tty_driver *moxaDriver;

static DEFINE_TIMER(moxaTimer, moxa_poll, 0, 0);

static DEFINE_SPINLOCK(moxa_lock);

static DEFINE_SPINLOCK(moxafunc_lock);



/*

 * HW init
@@ -1823,10 +1840,12 @@ static int MoxaPortSetTermio(struct moxa_port *port, struct ktermios *termio, 
	baud = MoxaPortSetBaud(port, baud);



	if (termio->c_iflag & (IXON | IXOFF | IXANY)) {

	        spin_lock_irq(&moxafunc_lock);

		writeb(termio->c_cc[VSTART], ofsAddr + FuncArg);

		writeb(termio->c_cc[VSTOP], ofsAddr + FuncArg1);

		writeb(FC_SetXonXoff, ofsAddr + FuncCode);

		moxa_wait_finish(ofsAddr);

		spin_unlock_irqrestore(&moxafunc_lock);



	}

	return baud;
@@ -1879,12 +1898,10 @@ static int MoxaPortLineStatus(struct moxa_port *port) 
	int val;



	ofsAddr = port->tableAddr;

	if (MOXA_IS_320(port->board)) {

		moxafunc(ofsAddr, FC_LineStatus, 0);

		val = readw(ofsAddr + FuncArg);

	} else {

	if (MOXA_IS_320(port->board))

		val = moxafuncret(ofsAddr, FC_LineStatus, 0);

	else

		val = readw(ofsAddr + FlagStat) >> 4;

	}

	val &= 0x0B;

	if (val & 8)

		val |= 4;